What is viscosity method?
Viscosity is the measure of a substance’s resistance to motion under an applied force. The formula for measuring viscosity is fairly simple: viscosity = shear stress / shear rate. The result is typically expressed in centipoise (cP), which is the equivalent of 1 mPa s (millipascal second).
What are the methods for measuring viscosity?
5 Ways to Measure Viscosity
- Capillary Viscometers.
- Rotational Rheometry.
- Vibrating Viscometers.
- Microfluidic Rheometers.
- Non-Contact Rheology.
- Viscosity Measurements with Formulaction.
What is unit of viscosity?
The unit of viscosity, accordingly, is newton-second per square metre, which is usually expressed as pascal-second in SI units. The viscosity of liquids decreases rapidly with an increase in temperature, and the viscosity of gases increases with an increase in temperature.
What are the different types of viscosity?
Viscosity is a fundamental material property when studying fluid flow for any application. The two most common types of viscosity are dynamic and kinematic. The relationship between these two properties is quite straightforward.
What factors affect viscosity?
Factors Impacting Viscosity Fluid viscosity changes with temperature. Pressure has a small impact on gas viscosity and the pressure impact on the viscosity of a liquid is very small….
What causes high viscosity?
An increase in blood viscosity can be caused either by a deformity of the shape of red blood cells (RBCs) which causes RBC aggregation and decreased blood flow or by any pathological elevation of the components of blood. This includes RBC, WBC, platelets, or serum proteins….
Does viscosity increase with density?
There is no direct relation between viscosity and density. In general, for any fluids, when the temperature is increased, its density decreases, thus the fluid becomes less viscous. ……
Does branching increase viscosity?
The smaller coil size of a branched chain will tend to decrease the viscosity, although branches long enough to entangle produce a broadened terminal zone and larger viscosity.
Does branching increase crystallinity?
Both the degree of branching as well as the length of the branches affects the density which can vary considerably. Typically, the higher the density of the polymer the higher the degree of crystallinity and the stiffer, harder, and stronger the polymer. However, these polymers are rather brittle.
Does branching increase density?
The general explanation given is that the chains are further apart, so the intermolecular forces are less, and as they are further apart, they occupy more volume, and the density is lesser….
Are branched polymers flexible?
An example of the effect of branching on physical properties can be found in polyethylene. Low-density polyethylene (LDPE), on the other hand, has significant numbers of both long and short branches, is relatively flexible, and is used in applications such as plastic films.
Why are polymers elastic?
The long polymer chains cross-link during curing, i.e., vulcanizing. The elasticity is derived from the ability of the long chains to reconfigure themselves to distribute an applied stress. The covalent cross-linkages ensure that the elastomer will return to its original configuration when the stress is removed.
Why is LDPE more flexible than HDPE?
The polymer chains of LDPE are highly branched compared to HDPE. This branching prevents the chains from stacking neatly beside each other, reducing the intermolecular forces of attraction. This results in a plastic that is softer and more flexible, but which also has lower tensile strength.
Is PVC a branched polymer?
2.3 Linear, Branched, and Crosslinked Polymers Polyethylene, PVC, nylon 66, and polymethyl methacrylate are some linear commercial examples found in this book. Branched polymers can be visualized as a linear polymer with side chains of the same polymer attached to the main chain.
What are the 2 types of polymers?
There are many types of polymers including synthetic and natural polymers….
What are the 3 main types of polymers?
From the utility point of view they can be classified into three main categories: thermoplastics, elastomers and synthetic fibers. They are commonly found in a variety of products worldwide. A wide variety of synthetic polymers are available with variations in main chain as well as side chains.
Is PVC a condensation polymer?
A condensation polymer among the following is: i) Teflon ii) Polystyrene iii) Dacron iv) PVC. Dacron is a condensation polymer. The condensation polymers are formed by repeated condensation reaction between two different bi-functional or tri-functional monomeric units.
What are examples of condensation polymers?
Examples of natural condensation polymers include cellulose, starch, and polypeptide chains of proteins. Several synthetic condensation polymers discussed include nylon, kevlar, polyester, Bakelite, Melamine, polycarbonates, polyurethanes, epoxies….
Which is not a condensation polymer?
-Examples of molecules that undergo condensation polymers are Nylon-6, Dacron (or terylene) and Glyptal, etc. So, the correct answer is “Option B”.
Which one is classified as a condensation polymer?
Dacron is classified as a condensation polymer.As Polyesters are a type of condensation polymer ….
Is nylon 6/6 a condensation polymer?
It is a semicrystalline polyamide. Unlike most other nylons, nylon 6 is not a condensation polymer, but instead is formed by ring-opening polymerization; this makes it a special case in the comparison between condensation and addition polymers.
Is Teflon is a condensation polymer?
Addition polymers include polyethylene, polypropylene, Teflon, Lucite, and rubber. etc. Condensation polymers include nylon, Dacron, and Formica.
Is Glyptal a condensation polymer?
Dacron, Melamine and Glyptal are condensation polymers. Dacron (also known as terylene) is a polyester made by condensation polymerisation of ethylene glycol and dimethyl terephthalate.
What is Glyptal?
(ˈɡlɪptəl) n. (Chemistry) an alkyd resin obtained from polyhydric alcohols and polybasic organic acids or their anhydrides; used for surface coatings.
Which is incorrect for polymers?
Polymers made from a single monomeric species are called homopolymers whereas those made up of two or more different monomeric species are called copolymers. Polymers do not occur in nature….
Is Bakelite a condensation polymer?
Hence, Bakelite is a type of condensation polymer. The correct answer is option C. Note: Bakelite is the commercial name for the phenol-formaldehyde resin. This is a type of thermosetting polymer.